diff --git a/Lib/test/test_free_threading/test_itertools.py b/Lib/test/test_free_threading/test_itertools.py
index 7392bd739acd709..afcf77c8d3bad3f 100644
--- a/Lib/test/test_free_threading/test_itertools.py
+++ b/Lib/test/test_free_threading/test_itertools.py
@@ -4,6 +4,7 @@
     batched,
     chain,
     combinations_with_replacement,
+    count,
     cycle,
     permutations,
     tee,
@@ -142,5 +143,32 @@ def consume():
         self.assertEqual(errors, [], msg=f"unexpected errors: {errors}")
 
 
+class TestCountConcurrent(unittest.TestCase):
+    @staticmethod
+    def _spin_next(it, n=2000):
+        for _ in range(n):
+            next(it)
+
+    @staticmethod
+    def _spin_repr(it, n=2000):
+        for _ in range(n):
+            repr(it)
+
+    @threading_helper.reap_threads
+    def test_repr_racing_next_fast_mode(self):
+        for _ in range(10):
+            it = count()
+            workers = [self._spin_next] * 2 + [self._spin_repr] * 4
+            threading_helper.run_concurrently(workers, args=(it,))
+
+    @threading_helper.reap_threads
+    def test_repr_racing_next_slow_mode(self):
+        for _ in range(10):
+            # Large count to trigger "slow mode"
+            it = count(10**18, 2)
+            workers = [self._spin_next] * 2 + [self._spin_repr] * 4
+            threading_helper.run_concurrently(workers, args=(it,))
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2026-07-18-14-47-52.gh-issue-153981.yZcmKQ.rst b/Misc/NEWS.d/next/Library/2026-07-18-14-47-52.gh-issue-153981.yZcmKQ.rst
new file mode 100644
index 000000000000000..3fc3c3cca437c4b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-07-18-14-47-52.gh-issue-153981.yZcmKQ.rst
@@ -0,0 +1 @@
+Fix use-after-free race condition when calling :func:`repr` on :class:`itertools.count` under the :term:`free-threaded build`.
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index c0023c839ca7fe3..456f1150a209376 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -3675,27 +3675,34 @@ static PyObject *
 count_repr(PyObject *op)
 {
     countobject *lz = countobject_CAST(op);
-    if (lz->long_cnt == NULL) {
+    PyObject *long_cnt;
+
+    Py_BEGIN_CRITICAL_SECTION(lz);
+    long_cnt = Py_XNewRef(lz->long_cnt);
+    Py_END_CRITICAL_SECTION();
+
+    if (long_cnt == NULL) {
         Py_ssize_t cnt = FT_ATOMIC_LOAD_SSIZE_RELAXED(lz->cnt);
         return PyUnicode_FromFormat("%s(%zd)",
                                     _PyType_Name(Py_TYPE(lz)), cnt);
     }
 
+    long step = 0;
     if (PyLong_Check(lz->long_step)) {
-        long step = PyLong_AsLong(lz->long_step);
+        step = PyLong_AsLong(lz->long_step);
         if (step == -1 && PyErr_Occurred()) {
             PyErr_Clear();
         }
-        if (step == 1) {
-            /* Don't display step when it is an integer equal to 1 */
-            return PyUnicode_FromFormat("%s(%R)",
-                                        _PyType_Name(Py_TYPE(lz)),
-                                        lz->long_cnt);
-        }
     }
-    return PyUnicode_FromFormat("%s(%R, %R)",
-                                _PyType_Name(Py_TYPE(lz)),
-                                lz->long_cnt, lz->long_step);
+
+    /* Don't display step when it is an integer equal to 1 */
+    PyObject *msg = (step == 1)
+              ? PyUnicode_FromFormat("%s(%R)", _PyType_Name(Py_TYPE(lz)), long_cnt)
+              : PyUnicode_FromFormat("%s(%R, %R)", _PyType_Name(Py_TYPE(lz)),
+                                     long_cnt, lz->long_step);
+
+    Py_DECREF(long_cnt);
+    return msg;
 }
 
 static PyType_Slot count_slots[] = {